Youtube videos on Windows Vista

When I open youtube videos or google videos using my windows vista computer, I can see those videos in normal mode, but as soon as I choose to see them in full screen mode, all I see is a black screen but i can hear audio. Is this is a problem with my computer or this is a know windows vista issue or do I need to download some software on my computer? Any advice will be appreciated.

You Tube..... I have NVIDIA GeForce 6150 graphics with up to 559 MB shared video memory. I still get occasional blurry, opened up to full screen. I believe it is from their player or DVD recording efforts.